Optical code scanners are used in a wide variety of applications that rely on optical codes such as bar codes to store information. Industries such as retail, airline, self service, automotive, parcel delivery, pharmaceutical, healthcare and others use optical codes to provide inventory control, customer identification, product identification, item tracking and many others functions. Optical or bar code scanners are designed to scan an optical code that is typically attached to or printed onto an object. A common example of an optical code is a one dimensional (1D) linear bar code. A 1D bar code is comprised of a number of bars separated by spaces. Information is encoded on the bar code by varying the width of the bars and spaces. This is known as horizontal encoding. When the bar code is placed within the field of view of an optical code scanner, the scanner will detect and analyze the bars and spaces comprising the bar code and then decode the information encoded in the bar code. This operation is also called scanning or reading a bar code. Information encoded on a 1D bar code usually takes the form of ten to twenty alphanumeric numbers. Laser based optical scanners can read 1D bar codes very quickly and thus allows high pass-by speeds for the bar code.
Conventional 1D bar codes are not the only types of bar codes in use. Two dimensional or 2D bar codes are sometimes used when relatively large amounts of information must be encoded into a bar code. A 2D bar code encodes information in both the horizontal and vertical directions and can encode hundreds of characters into a bar code that uses a relatively small area.
Applications that require high pass-by scanning rates use lasers to read the bar codes. Unfortunately, optical code scanners based on lasers are best adapted to read 1D bar codes. 2D bar codes are difficult or in some cases impossible to read with a laser based optical code scanner. Therefore, what is needed is a way to maintain the high pass-by scanning rates for 1D bar codes while also being able to read 2D and other types of bar codes not read by a laser scanner.